UCHPC'08 First technical session on UnConventional High Performance Computing in conjunction with The 2008 International Conference on Computational Science and Its Applications (ICCSA 2008). Call For Papers: http://www.hig.se/~aht/uchpc/uchpc08.html GPU's are often used for HPC in the so called field "General-purpose computing on GPU's" (GPGPU). One limitation has been that only single precision is available, but double precision GPU's are already on the way. Also the Playstation 3 (PS3) has a lot of computing power for a very low cost and many researchers seem to be interested in the cell-based (Cell BE) architecture for HPC. One current trend is to build clusters of such devices. The GPU is today very often used for HPC, so it has started to be conventional. The Cell BE processor has just entered the market and there will probably be many exciting applications in HPC using them in the future. But to use the PS3 was a quite unconventional approach when the first cluster of PS3's was introduced in February this year. Furthermore there are many ways a FGPA can be used and some may seem unconventional now but might be standard in the future. The word “UnConventional” in the conference title emphasizes that hardware is used for HPC which was not intended for HPC in the beginning. So in some sense we try to capture things in this conference that are being done in an unconventional way today but perhaps will be conventional tomorrow. That is why the C in UnConventional is in capital letters.